Year	Percent
1991	44.127
1992	46.817
1993	45.943
1994	46.179
1995	47.514
1996	46.849
1997	47.722
1998	49.293
1999	48.19
2000	48.204
2001	49.711
2002	50.137
2003	48.369
2004	50.033
2005	49.551
2006	49.977
2007	50.964
2008	51.044
2009	52.809
2010	52.809
2011	53.04
2012	52.875
2013	53.482
2014	53.849
2015	54.126
2016	54.42
2017	54.54
2018	54.714
2019	54.842
2020	55.095
2021	55.254
2022	55.394